These are questions that climate scientists must ask, especially if they want to understand the cause of natural climate fluctuations of varying duration. (sciencedaily.com)
By varying the duration and intensity of a workout session, you can aim to achieve specific results. (bodybuilding-wizard.com)
During the initial crate training period, be sure to place your dog in the crate for short periods (of varying duration) when you are at home. (paw-rescue.org)